Question

which best explains why making a pancake from batter is an example of a chemical change?
the pancake that forms is a different state of matter.
the change from batter to pancake can be reversed.
a new substance forms when the batter is cooked.
the batter changes shape when it is cooked.

Explanation:

A chemical change results in the formation of a new substance. When batter is cooked to make a pancake, a new substance (the pancake) forms due to the chemical reactions that occur during cooking (such as proteins denaturing, starches gelatinizing etc.). A change in shape (as in "The batter changes shape when it is cooked") is a physical change. A change from batter to pancake being reversible would imply a physical change (like water freezing and melting). A pancake being a different state of matter (if that was the case, say from liquid batter to solid pancake) could be a physical change (like freezing). But the key indicator of a chemical change is the formation of a new substance.

Answer:

A new substance forms when the batter is cooked.